Cemented carbide cutting tools and processes for making and using

Abstract

Resharpenable cemented carbide cutting tools which have been treated by ion implantation, as well as a method of making and using these tools, are described. Applicants have found that the benefits of the initial ion implantation on cemented carbide tool life will remain after sharpening of the tool.

We claim: 
     
       1. A resharpenable cemented carbide cutting tool, said cutting tool having a cemented carbide cutting edge hardened by ion implantation and being resharpenable for reuse without further ion implantation, said cutting tool comprising: a first surface;   a second surface joining said first surface;   a cemented carbide cutting edge formed at the junction of said first and said second surfaces;   a wear-resistant layer located along said first surface and extending away from said cutting edge and said second surface beneath and parallel to said first surface to a depth of up to approximately 1000 angstroms, and intersects said second surface in a zone up to approximately 1000 angstroms wide; the hardening of the cutting edge by ion implantation along only said first surface and not along said second surface enabling resharpening of the cutting tool by removing material from said second surface, said second surface being hardened only in a zone up to approximately 1000 angstroms wide at the intersection of said first surface and said second surface.   
     
     
       2. The cemented carbide cutting tool according to claim 1 wherein said wear-resistant layer includes irradiation-damaged metal carbide particles and irradiation-damaged modified metallic binder. 
     
     
       3. The cemented carbide cutting tool according to claim 2 wherein said wear-resistant layer includes a foreign species implanted by ion implantation. 
     
     
       4. The cemented carbide cutting tool according to claim 1 wherein said wear-resistant layers extends inwardly up to 400 angstroms maximum. 
     
     
       5. The cemented carbide cutting tool according to claim 3 wherein said foreign species is nitrogen. 
     
     
       6. A resharpenable punch having a hardened cutting edge for use in perforating sheetlike material, wherein said punch comprises: a cemented carbide body having;   a leading face having a shape when viewed in plan similar to the shape of the perforation to be stamped,   a peripheral surface joined to said leading face,   a cutting edge formed at the junction of said peripheral surface and said leading face,   a layer of wear-resistant material substantially parallel to and extending inwardly away from only said peripheral surface up to approximately 1000 angstroms in depth, said layer of wear-resistant material being formed by implantation of ions,   and said layer of wear-resistant material intersecting said leading face only in a zone up to approximately 1000 angstroms wide, the punch being resharpenable by removing material from said leading face, the removal of material from said leading face being enabled by the relatively narrow zone of ion implanted material on said leading face at the intersection of said leading face and said peripheral surface.   
     
     
       7. The punch according to claim 6 wherein said layers of wear-resistant material includes irradiation-damaged cemented carbide. 
     
     
       8. The punch according to claim 7 wherein said layer of wear-resistant material further includes an implanted species. 
     
     
       9. The punch according to claim 8 wherein nitrogen comprises said implanted species. 
     
     
       10. A resharpenable die comprising a cemented carbide body, said die being hardened by ion implantation and being resharpenable for reuse without further ion implantation, said die having; a top face,   a bottom face,   a die cavity wall communicating between said top face and said bottom face,   a cutting edge formed at the junction of said die cavity wall and said top face,   a layer of wear-resistant material substantially parallel to and extending inwardly up to approximately 1000 angstroms away from said die cavity wall, said layer of wear-resistant material resulting from ion implantation,   and said layer of wear-resistant material intersecting said top face only in a zone up to approximately 1000 angstroms wide, said die being resharpenable and reusable without further ion implantation by removal of material from said top face, removal of material from said top face being enabled by ion implantation along only said die cavity wall, resulting in a zone of ion implantation of approximately only 1000 angstroms wide about the intersection of said top face with said die cavity wall.